Fix issue 2799: add some configuration items. (#2811)

* Fix issue 2799: add some configuration items.

spring-cloud-alibaba-examples/nacos-example/nacos-discovery-example/readme-zh.md

@@ -200,6 +200,9 @@ Metadata|spring.cloud.nacos.discovery.metadata||使用Map格式配置
 日志文件名|spring.cloud.nacos.discovery.log-name||
 接入点|spring.cloud.nacos.discovery.endpoint|UTF-8|地域的某个服务的入口域名，通过此域名可以动态地拿到服务端地址
 是否集成Ribbon|ribbon.nacos.enabled|true|
+集群|spring.cloud.nacos.discovery.cluster-name|DEFAULT|Nacos集群名称
+是否开启Nacos Watch|spring.cloud.nacos.discovery.watch.enabled|true|可以设置成false来关闭 watch
+是否启用Nacos|spring.cloud.nacos.discovery.enabled|true|默认启动，设置为false时会关闭自动向Nacos注册的功能
 
 
 

spring-cloud-alibaba-examples/nacos-example/nacos-discovery-example/readme.md

@@ -206,7 +206,9 @@ AccessKey|spring.cloud.nacos.discovery.access-key||
 SecretKey|spring.cloud.nacos.discovery.secret-key||
 Metadata|spring.cloud.nacos.discovery.metadata||Extended data, Configure using Map format
 log name|spring.cloud.nacos.discovery.log-name||
+cluster|spring.cloud.nacos.discovery.cluster-name|DEFAULT|Nacos cluster name
 endpoint|spring.cloud.nacos.discovery.endpoint||The domain name of a service, through which the server address can be dynamically obtained.
+enable Nacos Watch|spring.cloud.nacos.discovery.watch.enabled|true|Switch it to false to disable nacos watch
 Integration Ribbon|ribbon.nacos.enabled|true|
 enabled|spring.cloud.nacos.discovery.enabled|true|The switch to enable or disable nacos service discovery